
#ifdef GL_ES
precision mediump float;
#endif

const float PI=3.1415926535;

uniform vec2 u_resolution;
uniform float u_time;

float circleshape(vec2 position,vec2 center,float radius){
    return step(radius,length(position-center));
}

void main(){
    
    vec2 coord=gl_FragCoord.xy/u_resolution;
    vec3 color=vec3(0.);
    
    float transRadius = 0.5 ; 
    float transX = cos(u_time)*transRadius;
    float transY = sin(u_time)*transRadius;
    vec2 translate=vec2(transX,transY);
    coord+=translate;
    
    color+=vec3(circleshape(coord,vec2(.5),.3));
    
    gl_FragColor=vec4(color,1.);
    
}

